Chapter 35: Female genitalia

The female genital organs
comprise the ovaries, uterine tubes, uterus, vagina, and external
genitalia (fig. 35-1). The vagina is situated partly in the pelvic
cavity and partly in the perineum. The internal organs can be examined
by an electrically lit tubular instrument inserted into the peritoneal
cavity (laparoscopy).

An ovary is an ovoid gland that produces oocytes and secretes steroid
hormones. It is commonly situated on the lateral wall of the pelvis
(typically in the angle between the external iliac vein and the
ureter), where it can be palpated bimanually. The ovary presents tubal
and uterine ends, medial and lateral surfaces, and mesovarian and free
borders. The superior, or tubal, end, closely related to the uterine
tube, is attached to the suspensory ligament ofthe ovary. The inferior,
or uterine, end is attached to the ovarian ligament. The medial surface
is related to the uterine tube and the ileum. The lateral surface is in
contact with the parietal peritoneum that lines the side wall of the
pelvis. The anterior, or mesovarian, border is attached to the
mesovarium, and it contains the hilum of the ovary. The posterior, or
free, border is related to the uterine tube and ureter.

Ligaments.

The ovary is anchored to the posterior aspect of the broad ligament
by a double fold of peritoneum, the mesovarium, which is continuous
with the so-called germinal epithelium around the ovary. The suspensory
ligament of the ovary (or infundibulopelvic ligament) ascends to become
lost in the connective tissue of the pelvis. The ovarian artery
descends in the suspensory ligament and, by way of the broad ligament
and mesovarium, enters the hilum of the ovary. The ovarian ligament
connects the ovary to the body of the uterus, immediately posterior to
the opening of the uterine tube.

The uterine tubes are paired conduits between the ovaries and the
uterus. The uterine tube transmits oocytes from the ovaries and
spermatozoa from the uterus. It is the usual site of fertilization, and
it conveys the early embryo to the uterine cavity.

The uterine tubes develop as outgrowths of the peritoneal cavity;
they maintain this continuity and thereby allow communication between
the peritoneal cavity and the exterior of the body. The Greek word
salpinx, meaning "tube," is used in such compounds as mesosalpinx.

Each uterine tube is situated in the superior, free border and between
the layers of the broad ligament. The uterine tube is subdivided
into four parts, from lateral to medial: the infundibulum, ampulla,
isthmus, and uterine part. The infundibulum, which is closely
related to the ovary, contains the abdominal opening of the uterine
tube, by which the tube is in communication with the peritoneal cavity.
Oocytes pass from the ovary through the abdominal opening and along the
uterine tube. The fimbriae are irregular fringes that project from the
margin of the infundibulum, and one (ovarian fimbria) may be longer
than the others. The ampulla, the longest and widest part, continues
gradually into the isthmus. The uterine part, which lies in the wall of
the uterus, contains the uterine opening of the uterine tube.

Patency of the uterine tubes can be demonstrated radiographically
(hysterosalpingography) by the injection of a radio-opaque medium into
the uterus (fig. 35-3).

The uterus is a muscular organ in the lining of which the embryo
becomes implanted and in which the embryo and fetus develop. The
uterine cavity receives the openings of the uterine tubes, and the
uterine cavity and vagina (the "birth canal") allow the exit of the
fetus at birth (fig. 35-6). The Greek words hystera and metra are used
in such compounds as hysterectomy and endometrium. The uterus has three
layers: a mucosa (the endometrium), a muscular coat (the myometrium),
and a serosa (the perimetrium).

Parts.

The nulliparous uterus resembles an inverted pear and consists of
two main parts: the body and the cervix. The body is twice as long as
the cervix, whereas the converse is true in the newborn. The body
includes the fundus, which is the portion that lies superior and
anterior to the openings of the uterine tubes. The body is usually
tilted anteriorly onto the bladder (anteflexion, see fig. 35-4),
which is separated from the uterus by the uterovesical pouch. Superior
and posterior, the body is separated from the rectum by the
recto-uterine pouch (see fig. 35-4), which usually contains coils of ileum.
Right and left margins are anchored to the broad ligaments. The
region between the body and cervix is referred to as the isthmus:
during pregnancy, it is known as the "lower uterine segment." The
cavity of the isthmus was formerly called the "internal os." The cervix
extends inferiorward and posteriorward and usually forms approximately
a right angle with the vagina (the angle of anteversion, see fig. 35-4). As
the bladder fills, the uterus tends to become retroverted. The
cervix may be considered in two parts: (1) a supravaginal portion
superior to the limits of the vagina and (2) a vaginal portion, which
projects into the cavity of the vagina (see fig. 35-4). The
cavity of the uterine body, which is somewhat triangular in coronal
perspective (see fig. 35-2), is slit-like in sagittal section (see fig. 35-1). The
canal of the cervix communicates with the vagina by the external os,
which is bounded by anterior and posterior lips. The entire uterine
cavity can be demonstrated radiographically by hysterosalpingography
(see fig. 35-3).
The uterus can be palpated bimanually (fig. 35-7).
Dilatation (of the cervical canal) and curettage (scraping of the
uterine lining) are performed for diagnostic or therapeutic purposes.

Peritoneal Relations.

The uterus is supported by being anchored to the vagina and by its
peritoneal and fascial attachments to nearby structures. The peritoneum
is reflected from the bladder (uterovesical pouch) to the isthmus uteri
and then over the fundus and onto the posterior aspect of the cervix
(recto-uterine pouch) and vagina (see figs. 35-1 and 35-4).

Ligaments.

The peritoneum that covers the uterus continues laterally as a
double fold known as the broad ligament (figs. 35-2 and 35-8). The
ligament extends to the lateral wall of the pelvis and serves as a
mesentery for the uterine tube, which lies between its two layers. This
part is the mesosalpinx, whereas the part adjacent to the uterus is
called the mesometrium. The posterior layer of the broad ligament forms
the mesovarium. In addition to the uterine tube, the broad ligament
contains connective tissue (the parametrium), the uterine and ovarian
vessels, the round and ovarian ligaments, and some embryonic remnants
(e.g., the epoophoron, which consists largely of a duct parallel to and
below the uterine tube) (fig. 35-8B). The round ligament is a fibrous band
attached to the uterus immediately inferior to the entrance of the
uterine tube. It extends laterally and anteriorly, hooks around the
inferior epigastric artery, traverses the inguinal canal, and
terminates in the labium majus. The round ligament is accompanied in
the fetus, and occasionally in the adult, by a process of peritoneum,
the processus vaginalis. The visceral pelvic fascia on the lateal
aspect of the cervix is thickened as the lateral (or transverse)
cervical (or cardinal) ligament and as the uterosacral ligament on the
posterior aspect (see fig. 35-5).

Blood Supply.

The uterine arteries (fig. 35-9) provide the main blood supply. Each artery
ascends between the layers of the broad ligament, near the lateral
margin of the body, and supplies branches to both anterior and
posterior surfaces. The uterine venous plexus is connected with the
superior rectal vein, thereby forming a portalsystemic anastomosis.

Lymphatic Drainage.

The fundus and upper part of the body drain into the lumbar (aortic)
nodes, the lower part of the body into the external iliac nodes, and
the cervix into the external and internal iliac and the sacral nodes.

The vagina serves for copulation, as the lower end of the birth canal,
and as the excretory duct for the products of menstruation. The cavity
of the vagina communicates with that of the uterus, and it opens into
the vestibule below. The vagina extends inferiorly and anteriorly,
parallel to the plane of the pelvic inlet.

The anterior and posterior walls of the vagina are about 7.5 and 9 cm
long, respectively. They are highly distensible and are in contact
inferior to the cervix. The recess between the vagina and the vaginal
part of the cervix consists of a continuous anterior, lateral, and
posterior fornix. The posterior fornix, which is the deepest, is
related to the recto-uterine pouch. The opening of the vagina into the
vestibule may be partially closed by a fold called the hymen (see fig. 38-5).

Relations.

The vagina is related anteriorly to the cervix, ureters, and bladder
and is fused with the urethra. Posteriorly, the vagina is related to
the recto-uterine pouch, the rectum, and the perineal body. The lateral
fornix of the vagina is related to the ureter and uterine artery. The
pubococcygeal muscles act as a sphincter for the vagina. The vagina is
supplied by branches (including uterine and vaginal) of the internal
iliac artery.

The vagina and cervix can be inspected through a speculum in the
vagina. Digital examination per vaginum may be combined with
palpation through the anterior abdominal wall by the other hand
(bimanual examination). The following structures are palpable per
vaginam:

1. Anteriorly-urethra, vaginal part of cervix, distended bladder, and
body of uterus bimanually

Questions

35-1 The ovary is commonly situated on the
lateral wall of the pelvis, where it can be palpated bimanually (Le.,
with one hand on the abdomen and the other per vaginam). The long axis
is vertical (see fig. 35-1), and not horizontal as shown in most
illustrations, where the broad ligaments and uterine tubes have been
spread out (see fig. 35-2).

35-2 The ovary is covered by the so-called
germinal epithelium, which is continuous with the mesothelium of the
peritoneum. The term superficial epithelium is preferable to germinal
epithelium because the primordial germ cells are now believed to arise
extragonadally. The corresponding covering of the testis is the
visceral layer of the tunica vaginalis.

35-4 The broad ligament may be regarded as
the mesentery of the uterine tube. It extends from the margin of the
uterus to the lateral wall of the pelvis.

35-5 Which Latin terms and Greek roots are
associated with the ovary, uterine tube, and uterus?

35-5 Some Latin terms and Greek roots
associated with the genitalia are testis and orchis; ovarium and
oophoros; tuba uterina and salpinx; uterus, hystera, and metra; and
vagina and kolpos. All these are used in various compounds (e.g.,
salpingitis and hysterectomy) and illustrate the Latin and Greek
origins of medical terminology. Many aspects ofthe uterus are discussed
in R. M. Wynn (ed.), Biology of the Uterus, 2nd ed., Plenum, New York,
1977.

35-6 The endometrium is the mucosa of the
uterus. That of the cervix is sometimes distinguished as endocervix.
The presence of extra-uterine endometrium (e.g., in the ovary or
elsewhere in the pelvis) is known as endometriosis. The endometrium of
pregnancy is termed decidua (L., falling off; cr. deciduous trees,
deciduous teeth), because it is shed after parturition.

35-7 The uterus is normally anteverted,
i.e., the cervix is directed inferiorward and posteriorward at slightly
more than a right angle to the vagina (see fig. 35-4). The
uterus is also generally anteflexed, i.e., the body is bent
inferiorward and anterorward at the isthmus. Filling of the bladder
tends to push the uterus into a relatively retroverted position.

35-9 Hysterosalpingography, as its name
suggests, is the (radiographic) depiction of the uterine and tubal
cavities (see fig. 35-3). In addition to demonstrating tubal patency,
it allows the detection of various anomalies of the uterus. For
examples, the uterus may be partially divided into right and left horns
(uterus bicornis unicol/is). Good accounts of uterine anomalies are
given by I.W. Monie and L.A. Sigurdson (Am. J. Obstet. Gynecol.,59:696,
1950) and by E. Zanetti, L. R. Ferrari, and G. Rossi (Br. J. Radiol.,
51:161, 1978).

35-11 The uterus is supported by the
vagina, by muscles (pelvic and, perhaps, urogenital diaphragms), and by
ligaments and folds. The uterus is connected to the bladder by the
uterovesical fold and to the rectum by the recto-uterine and recto
vaginal folds. Fascial thickenings form the lateral cervical, or
cardinal, ligament (see fig. 35-5) and the uterosacral ligament. The broad
ligaments proceed to the lateral wall of the pelvis, and the round
ligaments enter the inguinal canals.

Figure 35-3
Hysterosalpingograms, showing the uterus and uterine tubes. In A, note
the cavity of the uterus, uterine tubes, and the bilateral "spill" of
the radio-opaque medium into the peritoneal cavity, thereby
demonstrating the patency of the tubes. B, View from in anterior and
superior. Note the slit-like shape of the uterine cavity in this view.
Note also the thickness of the uterine wall. (A, Courtesy of Sir Thomas
Lodge. B, Courtesy of Robert A. Arens, M.D., Chicago, Illinois.)

Figure 35-4
The uterus. A shows the parts of the organ. B shows the normal position
of anteflexion and anteversion. C shows the angle (a) of anteversion. D
represents a retroverted uterus. E shows the uterovesical and
recto-uterine pouches. F demonstrates the principle of (1) abdominal
and (2) vaginal hysterectomy (arrows).

Figure 35-5
Horizontal section of the pelvic viscera, showing the ligaments of the
uterus. The arteries shown are, from posterior to anterior, the middle
rectal, uterine, and inferior and superior vesical.

Figure 35-6
A, Fetus at term in utero, cephalic presentation. Note the fetal
vertebrae and ribs, bones of the limbs, and skull. The parietal bones
have overlapped the frontal bone at the coronal suture. H, Infant
during birth. Cf. fig. 31-6, lowest position (A, Courtesy of Robert A.
Arens, M.D., Chicago, Illinois. B, Courtesy of Robert P. Ball, M.D.,
Oak Ridge, Tennessee.)

Figure 35-8
Sagittal sections of (A) left and (B) right broad ligaments, showing
their relationships to the ovaries and uterine tubes. B shows embryonic
remnants.

Figure 35-9
The blood supply to the female reproductive system. Extensive
anastomoses occur between the ovarian and uterine arteries. Cervical
branches of the uterine arteries anastomose across the median plane.
The four-tiered concept of the reproductive system (A,B,C,D) is based
on anatomical, physiological, and pathological data and may perhaps
have embryological implications. For details see R. Contamin et al.,
Gynecol., 28:235-252, 1977.